1. Field of the Invention
This invention relates generally to microscope slide stainers.
2. Prior Art
Many types of biological specimens for microscopic examination are stained with color to increase contrast for better viewing. The process includes placing the specimen on a transparent microscope slide, applying a staining solution or reagent to the specimen, heating the specimen to a suitable temperature, and rinsing off the reagent. The staining process is very time consuming when done with separate equipment. Cross contamination between the slides occurs when they are transferred by hand from one piece of equipment to another, and also when the slides are stained by being submerged in the same reagent container.
Many mechanized slide stainers have been disclosed for automating the process. A stainer disclosed in U.S. Pat. No. 5,770,346 to Edwards includes a conveyer for automatically taking slides stored around a carousel and transporting them across several staining stations, including a heating station, and finally dropping them into a slide collection bin. A stainer disclosed in U.S. Pat. No. 4,738,824 to Takeuchi includes a robotic arm for dipping racks of slides in a plurality of baths. However, cross contamination occurs because the slides are submerged in the same baths. A stainer disclosed in U.S. Pat. No. 4,651,671 to Pedersen includes a plurality of pivoted robotic arms attached to a conveyer for dipping individual slides in a plurality of baths. Cross contamination also occurs because the slides are submerged in the same baths. A stainer disclosed in U.S. Pat. No. 4,413,584 to DiMaggio, Jr. et al. includes pivotable slide trays for tilting up the slides to assist runoff during rinsing. However, no heater is included. A stainer disclosed in U.S. Pat. No. 4,043,292 to Rogers et al. includes a carousel with radial arms for carrying slides to staining and heating stations. The arms are pivotable for tilting the slides. The slides are heated by being positioned on a heated platen. However, the wet slides will stick to the smooth top surface of the heated platen, so that they will be difficult to remove.
All fully automated slide stainers are complicated, and thus very expensive. They use large quantities of very expensive reagents. Many have transparent covers that allow radiated heat loss, which lengthens the warm up time. Many hold slides vertically, so that the slides cannot be observed during the staining process. Although some hold slides horizontally, they have darker or cluttered backgrounds that reduce contrast and hinder slide observation.
Accordingly, objects of the present microscope slide stainer are:
to stain-microscope slides;
to reduce human handling of the slides;
to heat the slides to selectable temperatures;
to start and stop heating very quickly;
to enable the slides to be seen clearly;
to prevent the slides from drying out;
to prevent the wet slides from sticking;
to tilt the slides to assist runoff during rinsing;
to prevent the runoff from each slide from crossing over onto adjacent slides; and
to prevent radiated heat loss for significantly faster warm up.
Further objects of the present invention will become apparent from a consideration of the drawings and ensuing description.
A microscope slide stainer includes a waste bin with an open top, and supporting notches arranged on the top edges of opposite sides. A slide supporting rack is supported in a horizontal position across the top of the bin in the supporting notches. The rack includes a pair of rails extending along a horizontal base. Brackets arranged on top of the rails define a plurality of spaced-apart slide holding positions. A hot plate is positioned between the rails and spaced above the horizontal base. A control box is attached to the hot plate for temperature control. Pins extending from opposite sides of the hot plate ride in direction-changing slots in the rails to enable the hot plate to be moved between a raised position engaged against the bottom of the slides, and a lowered position disengaged from the slides. Grooves are arranged on top surface of the hot plate to prevent the wet slides from sticking to it. A cover is removably positioned over the rack to define a heating and humidity chamber. The rack can be placed in a tilted position for rinsing the slides by inserting its ends in slanted slots extending downwardly from the supporting notches on the bin.